From fda93d92d7824159d8532995072dde2bee4bc4b3 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Mon, 20 Mar 2006 22:59:21 -0800 Subject: [BRIDGE]: allow show/store of group multicast address Bridge's communicate with each other using Spanning Tree Protocol over a standard multicast address. There are times when testing or layering bridges over existing topologies or tunnels, when it is useful to use alternative multicast addresses for STP packets. The 802.1d standard has some unused addresses, that can be used for this. This patch is restrictive in that it only allows one of the possible addresses in the standard. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/bridge/br_sysfs_br.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) (limited to 'net/bridge/br_sysfs_br.c') diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c index 6f577f16c4c..96bcb2ff59a 100644 --- a/net/bridge/br_sysfs_br.c +++ b/net/bridge/br_sysfs_br.c @@ -242,6 +242,54 @@ static ssize_t show_gc_timer(struct class_device *cd, char *buf) } static CLASS_DEVICE_ATTR(gc_timer, S_IRUGO, show_gc_timer, NULL); +static ssize_t show_group_addr(struct class_device *cd, char *buf) +{ + struct net_bridge *br = to_bridge(cd); + return sprintf(buf, "%x:%x:%x:%x:%x:%x\n", + br->group_addr[0], br->group_addr[1], + br->group_addr[2], br->group_addr[3], + br->group_addr[4], br->group_addr[5]); +} + +static ssize_t store_group_addr(struct class_device *cd, const char *buf, + size_t len) +{ + struct net_bridge *br = to_bridge(cd); + unsigned new_addr[6]; + int i; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + if (sscanf(buf, "%x:%x:%x:%x:%x:%x", + &new_addr[0], &new_addr[1], &new_addr[2], + &new_addr[3], &new_addr[4], &new_addr[5]) != 6) + return -EINVAL; + + /* Must be 01:80:c2:00:00:0X */ + for (i = 0; i < 5; i++) + if (new_addr[i] != br_group_address[i]) + return -EINVAL; + + if (new_addr[5] & ~0xf) + return -EINVAL; + + if (new_addr[5] == 1 /* 802.3x Pause address */ + || new_addr[5] == 2 /* 802.3ad Slow protocols */ + || new_addr[5] == 3) /* 802.1X PAE address */ + return -EINVAL; + + spin_lock_bh(&br->lock); + for (i = 0; i < 6; i++) + br->group_addr[i] = new_addr[i]; + spin_unlock_bh(&br->lock); + return len; +} + +static CLASS_DEVICE_ATTR(group_addr, S_IRUGO | S_IWUSR, + show_group_addr, store_group_addr); + + static struct attribute *bridge_attrs[] = { &class_device_attr_forward_delay.attr, &class_device_attr_hello_time.attr, @@ -259,6 +307,7 @@ static struct attribute *bridge_attrs[] = { &class_device_attr_tcn_timer.attr, &class_device_attr_topology_change_timer.attr, &class_device_attr_gc_timer.attr, + &class_device_attr_group_addr.attr, NULL }; -- cgit v1.2.3